We will develop highly sensitive and selective acoustic wave biosensor arrays with signal analysis systems to provide a fingerprint for the identification of a wide array of bacterial pathogens and environmental health hazards. We have developed an unique highly sensitive dual mode acoustic wave platform that, when combined with phage based selective detection elements, form a durable bacteria sensor. Arrays of these new real-time biosensors will be integrated to form a biosensor array on a chip. We will optimize advanced piezoelectric aluminum nitride (ALN) wide bandgap semiconductors, novel micromachining processes, advanced device structures, selective phage displays development and immobilization techniques, and system integration and signal analysis technology. This dual sensor platform can be programmed to sense in a gas, vapor or liquid environment by switching between acoustic wave resonate modes. Such a dual mode sensor has tremendous implications for applications involving monitoring of pathogenic microorganisms in the clinical setting due to their ability to detect airborne pathogens. This provides a number of applications including hospital settings such as intensive care or other in-patient wards for the reduction of nosocomial infections and maintenance of sterile environments in surgical suites. Monitoring for airborn pathogen transmission in public transportation areas such as airplanes may be useful for implementation of strategies for redution of airborn transmission routes. The ability to use the same sensor in the STW mode for liquid sensing is important for tracing the source of airbom pathogens to local liquid sources. Sensing of pathogens in saliva in the STW mode will be useful for sensing oral pathogens and support of decision-making strategies regarding prevention of transmission and support of treatment strategies.